1. WATER QUALITY AND TREATMENT OF WATERS How polluted is the water from your home, river/creek, and sea water? Darrylynn Majied, Morningside HS and Montse Plascencia, Hamilton HS

2. Introduction Our main objective is to analyze the water quality of four water samples: tap water, Stone Canyon Creek (UCLA), Alamo River and Red Hill (from Salton Sea). Basic water quality of these samples is analyzed: alkalinity, hardness, nutrients, suspended solids, chloride and sulfate. Coagulation/Flocculation was used to treat a mixture of Alamo River and Red Hill samples.

4. Hardness is caused by divalent cation e.g., calcium and magnesium.

6. Alkalinity of Alamo River and Salton Sea was ~ 200 mg/L as CaCO3

8. Nitrogen and Phosphorus Nitrogen species analyzed: ammonia, nitrite and nitrate. Phosphorus analyzed: ortho-Phosphate. Both nitrogen and phosphorus are nutrient that stimulates plant growth; however, excessive amount of this nutrient result in an algae bloom, which can reduce dissolved oxygen in water and adversely affect aquatic life.

10. Nitrate concentration in Red Hill exceeded 10 mg/L, limit set up US EPA.

12. High concentration of phosphate in Alamo River may be due to the fertilizer used by the farm land nearby.

14. Suspended Solids Suspended solids have a diameter greater than 2.5 um in size. Suspended solids can float and form unpleasant scum layers or sink and cause sediment buildup. High suspended solids can reduce aesthetic for recreational activities and visibility of waters. Turbidity is measured when the sample’s light is blocked by large amounts of silt, microorganisms, plant fibers, sawdust, wood ashes, chemicals and coal dust. In other words, any substance that makes the water cloudy will cause turbidity.

17. Sulfate and Chloride Both sulfate and chloride ions are monitored in waters due to their effects on the taste (chloride) and odor (sulfate) in high concentration. High concentration of sulfate ion can also cause scaling and corrosion in water pipes. Hydrogen sulfide (“rotten-eggs smell”) is released under anaerobic (no oxygen) condition.

19. The sulfate and chloride concentrations of Alamo River is 1/10 and 1/20 of those of Red Hills, respectively.

21. We used a chemical treatment (coagulation and flocculation) for this study.

22. Coagulation and flocculation is a process that allow particles to react and grow in size; bigger floc will form due to an addition of a coagulant (e.g. aluminum sulfate) to the water.

24. Process of TSS combining.

25. The end results of coagulation. Observe both beakers, which one is more clear. Therefore coagulation is a method of treatment, causing the water to be more pure.

26. Conclusion Our results show the water quality of Alamo River and Red Hill from Salton Sea is more polluted than the tap water and Stone Canyon Creek. Treatment is urgently needed to improve the water quality of these two water bodies.

27. Acknowledgements UCLA Henry Samueli School of Engineering and Applied Science UCLA Center for Excellence in Engineering Diversity (CEED) Staff Howard Hughes Medical Institute (HHMI) Dr. Sim Lin Lau, Civil and Environmental Engineering Department